1. Field of the Invention
This invention relates to a process for the production of alcohols, more particularly to a process for the production of alcohols containing at least two carbon atoms from methanol, a process which is sometimes referred to as homologation, using a catalyst containing an oxide or uranium and/or thorium.
There are several processes available for the production of methanol from natural gas or from synthesis gas and it is probable that methanol will be produced and traded in increasing quantities in the near to medium term future. However, there is a need for alcohols containing two and more carbon atoms for use such as solvents, gasoline additives and chemical intermediates for a wide range of products. It is therefore an object of the present invention to provide a process for converting methanol into C.sub.2 and higher alcohols.
2. Description of Art
U.S. Pat. No. 1,562,480 describes the reaction of methanol with carbon monoxide to produce higher molecular weight compounds such as alcohols and aldehydes using a catalyst. The catalysts described contain a combination of metals and can contain hydrogenating metal constituent and a hydrating metal constituent. As examples of hydrogenating constituents are mentioned copper, silver, gold, tin, lead, antimony, bismuth, zinc, cadmium and thallium and as examples of the hydrating constituent are mentioned oxides of titanium, thorium, vanadium, niobium, manganese, cerium, lanthanum, tantalum, chromium, molybdenum, tungsten, uranium, didymium, glucinium and aluminum. The catalyst can have added alkali or alkaline earth metal compounds which are reported to be sometimes helpful in increasing the efficiency.
Further, U.S. Pat. No. 1,996,101 describes the reaction of methanol with carbon monoxide and hydrogen using an iron or cobalt-containing catalyst in which the iron or cobalt is present in an acid radical such as a ferrate or ferrite of an alkali or alkaline earth metal.
More recently the homologation of methanol using a homogeneous catalyst has been previously described, in particular catalysts containing cobalt and ruthenium optionally together with a phosphine and iodide have been disclosed.
For example, U.S. Pat. No. 4,126,752 describes a process for the conversion of methanol to ethanol in which the methanol is reacted with water in the liquid state and carbon monoxide using a Group VIII metal catalyst and a water soluble basic inorganic compound such as an oxide, hydroxide carbonate or bicarbonate of an alkali metal.
U.S. Pat. No. 4,405,815 describes a process for production of ethanol and acetaldehyde from methanol by reaction of the methanol with hydrogen and carbon monoxide using a catalyst system containing cobalt and an iodide promoter and a polydentate ligand such as phosphine.
U.S. Pat. No. 4,423,258 describes the conversion of methanol to ethanol by reaction with hydrogen and carbon monoxide in an inert solvent and using as catalyst a cobalt compound, a manganese compound and a tertiary phosphine.
The present invention provides an improved process using a heterogeneous catalyst for the conversion of methanol to alcohols containing at least two carbon atoms.